Rotary positioning control apparatus



Nov. 23, 1943. E. w; PAESSLER 2,334,724

ROTARY POSITIONING CONTROL APPARATUS Filed Dec. 29, 1942 I 3Sheets-Sheet l FIGJ. 2 I 6 9 /0 8 U 8/ 9 3 A 3 INVENTOR.

ER/c PEP/75554 ER BY E. w. PAESSLER 2,334,724

ROTARY POSITIONING CONTROL APPARATUS Nmn- 23, 1943.,

Filed Dec. 29, 1942 3 SheetS Sheet 2 IN VEN TOR.

Em: 14 P415551. 5/?

Nov. 23, 1943, wfP Ess 2,334,724

ROTARY POSITIONING CONTROL ATPARATUS.

Fi l'ed Dec. 29 1942 3 Sheets-Sheet 3 INVENTOR.

ERIC W P1 75554 5/? 1? TTOZNE) Patented Nov. 23, 1943.

ROTARY POSITIONING APPARATUS CONTROL Eric Walter Pae ssler, Hackensack,N. J assignor to Federal Telephone & Radio Corporation,

New York, N Y a corporation ofjDelaware Application December 29, 1942,Serial No. 470,468

6 Claims.

This invention relates to control and in particular to an apparatus forvarying apparatus the reactance of a radio frequency oscillatory circuitso that it may be automaticallytuned to.

a predetermined frequency. I

Many control devices of this general type are to be found in the priorart and considerable development work in the past few years has beendirected to their greater simplification and reliability as well as toreduction in size and decreased costs. The present invention is believedto bea distinct step forward. in the attainment of these goals.

.As above indicatedone of the principal uses for this type of controlapparatus is to rapidly vary the tuning of radio frequency circuits ineither transmitters or receivers wherein it is'desirable that any one ofa number of predetermined frequencies be selected .orchanged from onevalue to another in a minimum of time. With the device of my inventionthe pressing of a momentary contact initiates a cycle of operation whichin a few seconds will change the tuning of a radio circuit to any givenpredetermined frequency. If the requirements are such that more than onecircuit is to be tuned, either a plurality of devices or one deviceoperating on a plurality of circuits through suitable gearing may beemployed.

Accordingly it, is an object of my invention to devise a rugged controlapparatus capable of tuning the circuits of radio apparatus to apredetermined frequency.

Another object of my invention is to devise anautomatic means forresetting the control apparatus at the beginning of its operatingsequences.

Another object of my invention is to devise a a rotary positioningcontrol apparatus whose se quences of operation may be initiated by amomentary contact push button.

Another object of my invention is to devise a control apparatus having,a construction such that an operator may easily and readily adjust andreset the mechanism when it is necessary ample of "control apparatusaccording to my invention;

Fig. 2 represents an elevation in 'section on 7 line 2 2 in Fig. 1;

Fig. 3 represents an end elevation as seen from the line 3--3-in Fig. 1;N V

Fig. 4 is a plan view of the top of the Fig. 1 apparatus, showing thegear drive and clutch mechanism;

also held together by three rectangular spacers 3, 4 and 5 and a tie-rod6; The spacers and the tie-rod are more clearly shown in section in Fig.2.

The end plates I and 2 journal a control shaft or cam shaft 1. Avariable tuning reactance (not shown), which may be either a variablecapacitor, a variometer, or other variableelement, is connected withcontrol shaft 1 and rotated thereby to predetermined angular positionsrelative to a fixed radius of the shaft. It is the novel to change fromone set of predetermined frequencies to another.

The features of the control apparatus of my invention lie primarily inits simplicity of construction and in its relatively'small number ofparts, as will be discerned as I proceed with the specification anddescription in connection with the accompanying drawings in which;

Fig. 1 represents in side elevation and in partial section a completeassembly view of an exmannerin which the rotation of shaft J!Econtrolled by the operating mechanism which constitutes one of theprincipal features of my invention.

A spline or feathered key 8 extends along the control shaft or cam shaft1 from a point beneath the spur gear 54 to the clamping nut l2. Aplurality of spacers 9, each having a keyway for mating with thespline'B are mounted on the v shaft 1. Each spacer has a small shoulderl0 turned on one end thereof. Mounted between the spacers and on theshoulders III are selector cams H', which under operating conditions aresecurely clamped in position between the nut I2 and the collar l3 thelatter being secured to the shaft either by pinning or by a set-screwl4. Theshaft l is held fromaxial displacement by collar l3 held fast toshaft 1 by set-screw l4 cooperating with collar 13 on the opposite sideof plate I. On the periphery of each selector cam is a notch i5. Whenadjusting the tuning device prior to operation, each notch 15 assumes aposition corresponding to a predetermined frequency,

as will be more fully explained hereinafter.

When all of the selector cams are properly positioned with respect totheir notches i5, they are securely clamped as stated above.

"rality of reset washers 25.

1 the reset, washers and the 26 extending within thekeyway 21 and isemployed for manually resetting the mechanism Also mounted between theend plates I and 2, is a reset shaft |6. On this reset shaft, in spacedrelation, are mounted a plurality of members l1. Each member has threeextensions or arms I8, 20 and 22, the arm l8 being designated a detentarm and having a projection or detent l9 extending from its outer end asshown. The shape of the detent'corresponds'to the shape of the notch inthe control cam. Both are slightly tapered or wedge shaped so that whenin engagement no lost motion or backlash is permissible. The arm isdesignated a latch arm and together with the latch 31 functions tocontrol the operation of the mechanism, as will behereinafter explained.The arm 22 is a spring armand between a hole in this arm and a support24 is a tension spring 23, Fig. 2. It will be noted that the support 24,spring 23, and several other elements have been removed from theapparatus shown in Fig. 1, in

order to show the structure behind these elements.

Also supported on reset shaft l6 are a plu- The washers are formed withan integral internal projection or key 26 which'extends into a key-way21, the latter extending throughout the length of shaft I6. Each resetwasher also has a bent-over portion 28 extending from its outer rim upand over the hub portionof the member H. The members l1 and 2,5 aremaintained in spaced relation by .thespacers- 29. These members are notsecurely clamped together as is the case of the controlcams, but arepermitted to hav a rotational slippage'or free motion. The collar 30 atone end of the shaft "5 and the collar 3| at the other end of the shaftposition the member I1 withrespect toand in alignment with the control Bearns The collar 3| is secured to the shaft by the set-screw. 32. Lever33, positioned on the shaft |6 between one of the reset washers 25collar 30, has an integral internal key during periods when theapparatus is' adjusted as a whole; to operate at given predeterminedfrequencies. I

Between the end plates and 2 is .a third shaft 34 on which are mounted aplurality of levers 35.- Each memberhas oppositely extending arms 36 and31 which in turn have bent-over portions-38 and 39 respectively. Theportions 38 and 39 function as armatures for the electromagnets 48 and49. 19 determines the limit of rotation of the levers 35. This stepextends the whole distance between the end plates and 2. The upper end40 of the arm 31 together with the surface 4| of the arm 20 functions asa latching device, as will.

be hereinafter more fully described. The levers are maintained insuitable spaced relation on the shaft 34 by spacers 42, collar 43 andcollar 44, the latter being fastened to the shaft 34 by set-screw 45.The levers 35 also have a limited amount of free angular motion as isthe case with the members l1 and the reset washers 25 on shaft I6.

The spacing members 4 and 5 have mounted thereontwo L-shaped members 46and 41 which act as supports for electromagnets 48 and 49. Theseelectromagnets 48 and 49 are fastened to the L-shaped members 46 and 41by passing their cores through slots in these members and riveting over.The L-shaped members are fastened to the supports 4 and 5 by means ofscrews 50 and 5|. The electromagnets 48 and 49 are mounted in two grdupsof five each in order to conserve on space requirements. By so doing thetotal length of the mechanism can be nearly halved. It will be seen thateach lever 35 contains two bent-over portions 38 and 39. The bent-overportion 38 on each of one set of alternate levers 35, serve as armaturesfor magnets 49, while the bent-over portions 39 on the other set ofalternate levers 35 serve as armatures for magnets 48, there being onlyone magnet 48 or 49 cooperating with any single lever 35.

- Referring now to Fig. 4, the spur gear 54, keyed to shaft 1 mates withspur gear 55, mounted on shaft 56, the latter also extending between andbeing 'journalled in the two end plates and 2 of the supportingframework. Mounted on the shaft 56 and pinned or otherwise fastenedthereto is a threaded sleeve 51. On one end of the sleeve is a clutchplate 58 having a hole in its center whereby it may move freely in anaxial direction along the surface of the sleeve 51, the clutch plate 58'being splined to the sleeve 51 to prevent relative rotational motiontherebetween. A compression spring 59 surrounding the sleeve 51 and heldin position by the adjustable threaded collar 60, presses clutch plate58 to the left in Fig. 4. A friction disc 6|, made of cork for example,is posi tioned between the spur gear 55 and the clutch plate 58. Thegear 55 is not keyed to the shaft but is driven through the clutchmechanism as a result of friction and axial pressure exerted by Anadjustable eccentric stop spring 59. A spur gear '63 is also pinned orotherwise fastened, such as by set screw 64, to the shaft 56. Axialmotion of the shaft 56in either direction is prevented by the hub of thespur gear 63 and the collar 62, both of which are fast to shaft 56 andacting as retaining collars on either side of the end plate I. Gear 63is rotated by a motor (not shown) and serves as the driving gear for thecomplete mechanism. Its rotation causes the rotation of the shaft 56,the sleeve 51 and the clutch plate 58. The latter drives the gear 55through the friction disc 6|.

Mounted on the right hand side of the ear 63, Fig. 4, is a pivoted lever65 which acts at the beginning of the operating cycle to reset or takeout of engagement any detent l9 which may have been positioned in notchl5. In the position shown in Fig. 3, the spring 66, having one endsupported by screw 61 fast to gear 63 and its other end passing througha hole in the upturned end 68 of the lever 65, holds the lever against astop pin 69 mounted on gear 63. The lever is pivotedly supported by gear63 at the point 10.

On the shaft |6 is supported a lever 1| having two arms 12 and 13.Integral with lever 1| is a key 14 which fits into the keyway 21 of theshaft l6, so that any rotation of lever 1| rotates shaft I6. Arm 13 ofthe lever 1| is held against an adjustable eccentric stop 15 by a spring16, one end of which passes through a hole in the arm 13 while the otherend is held in fixed position by the screw 11. When the gear 63 rotatesin the direction shown by the dotted arrow at the beginning of the cycleof operation, the upturned edge 18 of the lever 65 pushes the arm 12 oflever 1| in an upward or clockwise direction, Fig. 3, thus rotatingshaft |6 and disengaging any detent H) which may be positioned in notch|5, Fig. 2. As the rotation of gear 63 continues, theend -18 of lever 65passes beyond the arm 12 and the motion has no effect on the lever II,since the end 18 of lever 65 merely lifts over the end of the arm 12.

Fig. 7 is a' schematic wiring diagra'm of electrical circuits which, inconjunction with a driving motor (not shown), relays, cams, etc., op-

erates the control mechanism of my invention,

reduction gearing not shown. A selector switch I05 selects forenergization any one of the electromagnets 48 or 49 (see Fig. 2)depending upon the predetermined frequency to be selected. Themechanism, as illustrated and described, is suitable for determining anyone of a total of ten frequencies. However, for simplification of theschematic wiring diagram, only one set of five electromagnets 48 havebeen shown connected with the five position selector switch I05 forselecting for operation the desired one of magnets 48. It will beunderstood, however, that any desired number of magnets 48 and 49,greater or less than ten, may be provided with a corresponding number ofcontacts in switch I05 for selecting the desired magnet for operation,each magnet 48 or 49 being employed to control the selection of adifferent predetermined frequency.

A cycle of operation will now be described. The position of all cams,relays, etc., of Fig. '7, are shown in the position they will acquire-atthe end of a cycle of operation or in other words when thev drivingmotor is deenergized. When a new or different frequency is to beselected, the switch arm I06 of the selector switch is moved so as tomake contact with a predetermined switch point I01 corresponding to thenew frequency; The pressing of push button I08 closes two pair ofcontacts I09 and H0. The closing of contacts I09 completes a circuitfrom the positive terminal of battery I50 through contacts I09, contactsI on cam I03, conductor II2, winding of relay H3, conductor H4 to thenegative terminal of battery I50, thereby energizing relay I I3. iheenergization of this relay opens back contacts H5 and H6 and closesfront contacts H1 and H8. The closing of contacts II1 completes acircuit from the A. C. power supply I5I through motor field winding IOI,contact H1, conductor H0, conductor I20, contacts H (which aremomentarily closed when push button I08 is depressed), conductor I2I,conductor I22, back to the power source II. The motor operates to drivecams I03 and I04 in the direction indicated by the anows whereuponcontacts I23 and H4 are closed by the raising of tongue I32 by cam I04.Contacts L23 being in parallel with contacts I it] permit the release ofpush button I00 without disrupting the power supply to the motor whichcontinues to operate.

When relay II3 operates, it is locked by the closure of contacts H8 inparallel with contacts I00 over conductors I25 and I26. The motoradvances cam I03 until the tongue I21 falls into slot I28. At this pointcontact III opens, thereby deenergizing the winding of relay II3. Thisresults in the closure of contacts H5 and IIS and the opening ofcontacts I I1 and H8, thereby reversing' the direction of rotation ofthe motor and also the cams I03 and I04. The motor circuit is nowtracedfrom the A. C. power source I5I,

'field winding I02, conductor I29, contacts H6,

conductor II9, contacts I23, conductor I22 back 'to the power sourceI5I. The closure of contacts II5 completes a circuit'from the positiveterminal of battery I through contacts II5, conductor I30, contacts I24,winding of selected magnet'48, contacts I01 and arm I06 of selectorswitch I05 back to batteryI50. Cams I03 and I04 are now rotating in adirection opposite to that of the arrow shownthereon and continue to doso until'tongue I32 falls into'notch I33 of cam I04. Atthis point themotor is deenergized by the opening of contactsxl23 and the winding ofmagnet 48 is deenergized by the opening of contact I24. This completesthe-cycle of control circuit operation.

During the cycle of electrical operations above described the followingmechanical operations of the control mechanism take place. It is assumedthat in the beginning of any cycle the various parts of the controlmechanism'are in a position suchas is shown in Fig. 2. The detent I9 iswithin the notch I5 of one of the cams II, thus fixing the angularposition of reactance control shaft 1, corresponding to a certainpredetermined frequency. When some other predetermined frefull arrows asshown in Fig. '7. Gear 63 rotates shaft 56 to'which the sleeve 51 isfastened. Clutch plate 58 which is splined to sleeve 51 is rotated bythe latter. Spring 59 presses against clutch plate 58, which in turnforces the friction disc 6| against gear 55. This tends to rotate thegear 55, but at' the beginning of an operating cycle this rotationcannot take place since gear 55 is in mesh with gear 54 and this lattergear is prevented from rotating by the \detent I9 in notch I5. There istherefore a slippage of the clutch mechanism. However, gear 63 in itscounter-clockwise rotation, Fig.- 3, also rotates the lever 65 and theend 18 of this lever in pressing against arm 12 of lever 1I,' disengagesthe detent I9 from the notch I5. This disengaging is actually done bythe bent-over portion 28 of the reset washers 25, the latter being alsokeyed to the shaft I8. When this occurs the latch-arm 20 of the memberI1 raises and the spring 52 rotates the latch 31 into the position shownin Fig. 5, wherein the end 40 of arm 31 engages surface 4| and preventsarm 20 from clockwise rotation, thus preventing detent -I 9 fromlatching into notch I5, none of the operating magnets 48 or 49 beingenergized at this time. The withdrawal of the-detent I9 permits gear 54'and in turn all of the control cams to be operated through the clutchmechanism 58, 6|, 55. The rotation of gear 54 continues until the tongueI21 drops into slot I20 of the cam I03; see Fig. '1. At this point thereversal of the driving motor takes place and gear 63 through the clutchmechinto position under the detent I9 and since the armature 3B or 39 asthe casemay be has been pulled up by the operating magnet, the arm 20 isfree to rotate and the detent I9falls into the notch I5, thus stoppingthe rotation of all cams II and the gear 54-. mechanism again takesplace but the driving motor continues to rotate cams I03 and I04 untilthe tongue I32 falls into slot I33 at which time the cycle of operationis completed.

Let it now be assumed that one wishes to change the adjustment of one ofthe cams II so that the control apparatus will tune the radio apparatusto a difierent frequency. The nut I2 is loosened thereby relieving thepressure existing between all of the spacers 9 and the cams II. In ordernot to disturb the adjustments of other cams, the nut I2 is loosenedonly when the detent I9 is in the notch I5= of the cam which is to bereadjusted. After the nut has been loosened and the cams are free torotate, a manual turning of the knob 80 which is also splined to theshaft 1 rotates all cams except the one which is held in position by itsdetent IS. The oscillatory circuit reactance which is controlled by therotation of shaft I is varied by turning knob 80 until the desired newfrequency is obtained. The nut I2 is again tightened and the apparatusis now in adjustment for the new frequency. It will be seen that theprocedure for changing the frequency is of the utmost simplicity and isone of the features of the invention. In order to exert a certain amountof pressure between all spacers 9 and cams II, when the nut I2 isloosened, a spring washer 8|, located between the collar 82 and one ofthe cams I I, exerts sufficient pressure against the spacers and camsto-prevent any slippage which might otherwise accidentally occur.

The invention has been described primarily as a mechanism forautomatically tuning radio frequency circuits to predeterminedfrequencies. It is obvious, however, that the apparatus of my inventioncould be used in any arrangement where a predetermined setting of anymovable part is required and it-is intended that the scope of myinvention be not limited except in accordance with the following claims.

What is claimed is:

1. Rotary position determining means comprising an angularly movable camshaft, a plurality of spacers splined on said shaft, a plurality ofcircular cams, each provided with a notch on its periphery, mounted onand between said spacers,

A slippageof the clutch means for clamping said cams between saidspacerswhereby said notches may be fixed at predetermined angular positionsrelative to a fixed radius of said shaft; a reset shaft, a plurality ofmembers comprising detents and latch arms mounted on said reset shaft,each detent having an engaged and disengaged position with.

placed said disengaged position, means for latching said detents in saiddisengaged position during said forward direction ofrotation of saiddriving means, means for reversing said direction of rotation, and meansfor unlatching a predetermined one of said detents whereby saidunlatched detent may move to the engaged position with its cooperatingnotch and stop the motion of said cam shaft.

2. Rotary position determining means comprising an angularly movable camshaft, apluity of circular cams, each provided with a notch on itsperiphery, mounted on and between said spacers, means for clamping saidcams between said spacers whereby said notches may be fixed atpredetermined angular positions relative to a fixed radius of saidshaft; detent meanshaving engaged and disengaged positions with respectto cooperating notches on said cams, driving means for rotating said camshaft alternately in a forward direction and in a reverse direction,means for urging said detents to their disengaged positions at the startof said forward direction of rotation, means for latching. said de--tents in their disengaged positions, means for reversing said directionof rotation, and means for unlatching a selected one of said detentswhereby *said unlatched detent may move to the engaged position with itscooperating notch and stop the motion of said cam shaft.

3. In a rotary position determining control apparatus, a rotary controlshaft, a plurality of selector cams mounted on said control shaft, areset shaft, a plurality of detents mounted on said reset shaft, saiddetents having an engaged and a disengaged position, means on theperiphery of said selector cams for engaging with said detents atpredetermined positions of said control shaft, reset means mounted onsaid reset shaft, latching means for maintaining said detents in theirdisengaged position during certain periods of operation of the controlapparatus, means for releasing said latching means during certain otherperiods of operation of said apparatus, driving means for rotating saidcontrol shaft, and reset control means operative in response to saidrotation of said driving means for momentarily angularly moving saidreset shaft whereby all detents are placed in said disengaged position.

4. In rotary position determining control apparatus in accordance withclaim 3, the combination in which said reset control means comprises afirst lever pivotedly mounted on said driving means and a second levermounted on said reset shaft and in operative relationship with saidfirst lever.

5. In rotary position determining control apparatus in accordance withclaim 3, the combination in which said reset means mounted on said resetshaft comprises a plurality of reset washers, at least one of saidwasher-s having means for disengaging one of said detents in response tothe operation of said reset control means.

6. In rotary position determining control apparatus in accordance withclaim 3, in the combination in which said driving means include meansfor rotating said shaft alternately in a forward direction and in areverse direction and said reset control means is responsive to saidforward rotation. ERIC WALTER PAESSLER.

